The chances of anything coming from Mars were a million to one, but still, in The War of the Worlds, they came: they came, in aluminium cylinders the size of ships; they conquered, with their towering tripods and hellish heat rays; and then, believe it or not, they were beaten—by bacteria!

So the story goes. But the story’s not over—not now that the estate of H. G. Wells has authorised a superb sequel by science fiction stalwart Stephen Baxter which, while overlong, turns the terrific tale Wells told in his time into the foundation of something greater.

The Massacre of Mankindtakes place a decade and change since the aliens’ initial invasion, and though the Martians may have been beaten, it would be foolishness in the first to conclude that they’re completely defeated. As Baxter has it, all we did was knock out the scouts. And it seems that those scouts served their purpose perfectly, because when the bad guys come back, they come back bigger, and better. Add to that the fact that they’ve adapted; I dare say no mere microbe is going to be their undoing on this day.

We puny humans have learned a few lessons, too. From studying the artifacts abandoned by the Martians in the aftermath of the First War, we’ve developed better weapons, and managed to manufacture a few meatier materials. Alas, our advancement has made us arrogant. We’ve begun to believe we have the beating of our technological betters, when in truth the shoe’s on the other foot:

Many had believed that England would not be subject to a second Martian attack, but enough had believed it possible, and enough more had feared it, that the authorities had been compelled to prepare. The result had been a reconfiguring of our military and economy, of our international relationships, and a coarsening of the fabric of our society. All this had delivered a much more effective home army, and when the attack had finally come, the mobilisation, after years of planning and preparation, had been fast and effective.

But as a result of that promptness of mobilisation a little less than half the new British Army, as measured in numbers of regular troops and front-line materiel, was destroyed in the first minutes of the assault—most of the lost troops leaving no trace.

So it begins—again: another war that brings people as a species to its knees. But Baxter’s is a wider and worldlier war than Wells’. No deus ex machina “like the bacteria which had slain the Martians in ’07” nips this narrative in the bud, thus The Massacre of Mankind occurs over a period of years; nor is the carnage confined this time to Surrey and its surroundings. In the fast-escalating last act, we’re treated to chapters set in Melbourne and Manhattan, among others, as the menace from Mars eventually spreads—though why it takes our interstellar oppressors so long to look beyond the borders of little Britain is perhaps the plot’s most conspicuous contrivance.

It’s notable that our new narrator comments not on this quandary, however her more humane perspective is a welcome departure from The War of the Worlds’ in every other respect. Baxter casts “the great chronicler of the First War” as one Walter Jenkins, and the author of the Narrative does appear here as a sort of aged sage, predicting this and planning that. That said, the star of this more global story is his ex sister-in-law, the journalist Julie Elphinstone:

Let me warn the reader from the off that if it’s the grandeur of the cosmos that you want, all told in the lofty prose of a man who was once paid to scribble such stuff, then it’s another correspondent you should seek out. On the other hand if it’s an honest, factual account of my own experience you’re after—a woman who survived the First Martian War and had her life pulled to pieces in the Second—then I humbly submit this, history as I saw it.

Humble Miss Elphinstone may be, but her character is far from passive in Baxter’s narrative. Her role in the unfolding of the whole is in fact of significant import—more so even than Walter Jenkins’ was in Wells’ text. She’s not just an able narrator, but a pivotal participant, and her “extraordinary journey, one which took [her] from the lobby of the world’s tallest building in New York to the foot of a Martian fighting-machine in London—and beyond!” is a pleasure to observe.

But the greatest of this book’s numerous goods is its willingness to work with the world—indeed the worlds—of the original author’s envisioning. As Baxter asserts in the afterword, Wells’ text is essentially “an alternate history, with a ‘jonbar hinge,’ a branching point, coming in 1894 when a mysterious light on Mars is interpreted as the casting of a huge gun,” and The Massacre of Mankind carefully maintains that hinge rather than replacing it with a more modern model.

In short, the science of Baxter’s kitschy fiction takes its cues from the specious speculations made when The War of the Worlds was written and not the knowledge of the now, thus there’s some weird and wonderful stuff in here, such as “the commonality of the hominid form across the worlds,” not to speak of the worlds themselves: Mars with its canals and a “dripping wet” Venus—populated, possibly, by yet another intelligence greater than man’s.

The Massacre of Mankind is far from the first of its ilk, but of the several pseudo-sequels I’ve read, be they short-form or long, it’s far and away the most fitting and filling follow-up to one of science fiction’s great standard-bearers. It could have been a touch tighter—much of the second act is ultimately rendered redundant—and a little less reliant on certain mechanisms of intervention, but by and large, Baxter’s book is a smart and successful salute to a story that helped spawn a genre.

Niall Alexander is an extra-curricular English teacher who reads and writes about all things weird and wonderful for The Speculative Scotsman, Strange Horizons, and Tor.com. He lives with about a bazillion books, his better half and a certain sleekit wee beastie in the central belt of bonnie Scotland.